In pneumatic tires for automobiles, in order to increase the rigidity of the bead portion, there are cases in which a rubber chafer formed from a hard rubber is provided at the outer side portion of the bead portion. The upper end of this rubber chafer is connected to a sidewall rubber layer that forms the sidewall portion (refer to, for example, Patent Document 1).
By the way, due to the bead portion repeatedly receiving bending deformation due to traveling, there are cases in which the rubber chafer and the sidewall rubber layer peel apart.
In order to overcome this problem, it has been thought to increase the joined surface area of the rubber chafer and the sidewall rubber layer, and a pneumatic tire having a cross-sectional shape such as shown in FIG. 11 has been proposed. In this pneumatic tire, as shown in FIG. 11, an inner side piece 106A, an outer side piece 106B, that are provided at the radial direction inner end portion of a sidewall rubber layer 106 structuring a sidewall 104, are structured so as to contact and cover the tire axial direction inner surface, outer surface, respectively, of a rubber chafer 102 whose upper portion is tapered, such that the joined surface area of the sidewall rubber layer 106 and the rubber chafer 102 is made large and the joining thereof is strengthened.
In order to produce such a pneumatic tire, in the green tire producing step, a rubber extruded member 108, that has a cross-sectional shape such as shown in FIG. 12 and integrates the sidewall rubber layer 106 that is unvulcanized and the rubber chafer 102 that is unvulcanized, is produced, and thereafter, a rubber sheet 110 formed from the same type of unvulcanized rubber as the sidewall rubber layer 106 is affixed so as to cover a vicinity of the rubber chafer 102 end portion of the rubber extruded member 108.
Then, the rubber extruded member 108, to which this rubber sheet 110 is affixed, is affixed to the carcass outer side surface of the tire case that is undergoing production, and the pneumatic tire was produced.
    Patent Document 1: Japanese Patent Application Laid-Open No. 10-166416